Q525. Please explain how many leak detection surveys must be conducted a calendar year?  Must a facility indicate in advance how many surveys will be conducted in the year?

A525. For natural gas distribution, a facility, which is the collection of all distribution pipelines, metering stations, and regulating stations that are operated by an LDC, is required to do at least one facility wide leak detection survey per calendar year and has the option to conduct additional facility-wide leak detection surveys; if the facility selects this option, the additional facility-wide survey(s) must be completed during the same calendar year in order to account for fixing one or more leaks in the annual GHG report.  If the facility chooses to fix one or more leaks and conduct another survey to determine that the component is not leaking, it must conduct a facility wide leak detection survey in order to account for fixing the leak(s) in the annual GHG report.  As leaks are random in nature and while some leaks are fixed others are likely to occur.  Therefore, a comprehensive survey is the only statistically relevant manner by which to establish facility-wide leak emissions rates and account for leaks repaired.  Please see the response to comment EPA-HQ-OAR-2009-0923-1014-9 (Response to Comments, pp. 1281-1282, http://www.epa.gov/ghgreporting/documents/pdf/2010/Subpart-W_RTC_part2.pdf) for further details.  It is very important to note that the requirement to conduct additional facility-wide leak detection surveys should a company wish to account for fixing a leak does not preclude in any way a company from repairing a leak.  If a company chooses to conduct only one facility-wide leak detection survey in a calendar year but finds a leak during the survey, the company can and is encouraged to fix the leak.  The leak detected though, as noted above, must be reported as a leaker for the entire calendar year should the company choose not to conduct a second survey.

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